Wibaux, MT frost dates
Last spring frostMay 27median date
First fall frostSep 16median date
Growing season112 daysfrost-free
Hardiness zone4aZone 4a
How Wibaux compares
- In 8 years out of 10, the last spring frost in Wibaux falls between May 15 and June 13, a 29-day window. The first fall frost falls between September 2 and September 29.
- The median last frost is 8 days later than the Montana median of May 19.
- Its 112-day growing season is longer than 23% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 15 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a chart.
- The weather station records an average of 194 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 15 |
| 50% (median) | May 27 |
| 10% (safe for tender plants) | June 13 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 2 |
| 50% (median) | September 16 |
| 90% (late) | September 29 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Wibaux, MT
Wibaux, MT frost dates — last frost May 27, first frost Sep 16, zone 4a. whenisthelastfrost.com
Crop
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Start indoors: Mar 4 to Mar 18Transplant outside: Apr 29 to May 13
Start indoors: Mar 18 to Apr 1Transplant outside: Jun 10 to Jun 24
Start indoors: Mar 18 to Apr 1Transplant outside: Jun 10 to Jun 24
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 3 to Jun 17
Start indoors: Apr 1 to Apr 15Transplant outside: May 6 to May 20Sow outdoors: Apr 29 to Jun 3Plant for fall: Jul 22 to Aug 19
Start indoors: Apr 1 to Apr 15Transplant outside: Apr 29 to May 13Sow outdoors: Apr 29 to May 13Plant for fall: Jul 8 to Jul 29
Start indoors: Apr 1 to Apr 15Transplant outside: May 13 to May 27
Start indoors: Apr 1 to Apr 15Transplant outside: May 6 to May 20
Start indoors: Apr 1 to Apr 15Transplant outside: May 13 to May 27
Start indoors: Apr 15 to Apr 29Transplant outside: Jun 17 to Jul 1Sow outdoors: Jun 17 to Jul 1
Start indoors: Apr 15 to Apr 29Transplant outside: Jun 3 to Jun 17
Sow outdoors: Apr 15 to May 6Plant for fall: Jun 24 to Jul 15
Sow outdoors: Apr 15 to May 6Plant for fall: Jul 22 to Aug 12
Sow outdoors: Apr 22 to Jun 3Plant for fall: Aug 5 to Aug 26
Start indoors: Apr 29 to May 6Transplant outside: Jun 10 to Jun 17Sow outdoors: Jun 3 to Jun 17
Start indoors: Apr 29 to May 6Sow outdoors: Jun 3 to Jun 17Plant for fall: Jul 8 to Jul 22
Start indoors: Apr 29 to May 6Sow outdoors: Jun 3 to Jun 17
Start indoors: Apr 29 to May 6Transplant outside: Jun 10 to Jun 24
Sow outdoors: May 6 to Jun 3Plant for fall: Jun 24 to Jul 8
Sow outdoors: May 6 to Jun 3Plant for fall: Jul 8 to Jul 22
Sow outdoors: May 6 to May 27
Sow outdoors: May 13 to Jun 10Plant for fall: Jul 8 to Jul 22
Sow outdoors: May 13 to Jun 3Plant for fall: Jul 22 to Aug 12
Sow outdoors: Jun 3 to Jun 24
Sow outdoors: Jun 3 to Jun 17
Transplant outside: Jun 10 to Jul 1
Plant for fall: Sep 2 to Oct 7
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Wibaux, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 4 – Mar 18 | Apr 29 – May 13 | — | — |
| Peppers | Mar 18 – Apr 1 | Jun 10 – Jun 24 | — | — |
| Eggplant | Mar 18 – Apr 1 | Jun 10 – Jun 24 | — | — |
| Tomatoes | Apr 1 – Apr 15 | Jun 3 – Jun 17 | — | — |
| Lettuce | Apr 1 – Apr 15 | May 6 – May 20 | Apr 29 – Jun 3 | Jul 22 – Aug 19 |
| Kale | Apr 1 – Apr 15 | Apr 29 – May 13 | Apr 29 – May 13 | Jul 8 – Jul 29 |
| Broccoli | Apr 1 – Apr 15 | May 13 – May 27 | — | — |
| Cabbage | Apr 1 – Apr 15 | May 6 – May 20 | — | — |
| Cauliflower | Apr 1 – Apr 15 | May 13 – May 27 | — | — |
| Okra | Apr 15 – Apr 29 | Jun 17 – Jul 1 | Jun 17 – Jul 1 | — |
| Basil | Apr 15 – Apr 29 | Jun 3 – Jun 17 | — | — |
| Peas | — | — | Apr 15 – May 6 | Jun 24 – Jul 15 |
| Spinach | — | — | Apr 15 – May 6 | Jul 22 – Aug 12 |
| Radishes | — | — | Apr 22 – Jun 3 | Aug 5 – Aug 26 |
| Cucumbers | Apr 29 – May 6 | Jun 10 – Jun 17 | Jun 3 – Jun 17 | — |
| Zucchini & Summer Squash | Apr 29 – May 6 | — | Jun 3 – Jun 17 | Jul 8 – Jul 22 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 112 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | Apr 29 – May 6 | — | Jun 3 – Jun 17 | — |
| Melons & Watermelon | Apr 29 – May 6 | Jun 10 – Jun 24 | — | — |
| Carrots | — | — | May 6 – Jun 3 | Jun 24 – Jul 8 |
| Beets | — | — | May 6 – Jun 3 | Jul 8 – Jul 22 |
| Potatoes | — | — | May 6 – May 27 | — |
| Swiss Chard | — | — | May 13 – Jun 10 | Jul 8 – Jul 22 |
| Cilantro | — | — | May 13 – Jun 3 | Jul 22 – Aug 12 |
| Green Beans | — | — | Jun 3 – Jun 24 | — |
| Sweet Corn | — | — | Jun 3 – Jun 17 | — |
| Sweet Potatoes Warning: Your frost-free season is about 112 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 10 – Jul 1 | — | — |
| Garlic | — | — | — | Sep 2 – Oct 7 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Wibaux 2 E, MT weather station, 4 km away (elevation 2,697 ft (822 m)).
Frost dates near Wibaux
- Glendive May 3 · Oct 4
- Savage May 12 · Sep 25
- Mildred May 20 · Sep 22
- Baker May 16 · Sep 26
- Plevna May 21 · Sep 20
- Crane May 12 · Sep 25
- Fallon May 20 · Sep 22
- Bloomfield May 3 · Oct 4
- Lindsay May 26 · Sep 17
- Sidney May 11 · Sep 27
Frequently asked questions
When is the last frost in Wibaux, MT?
The median last spring frost in Wibaux, MT is May 27. There is still about a 10% chance of frost after June 13, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Wibaux, MT?
The median first fall frost is September 16, with about a 10% chance of frost before September 2.
How long is the growing season in Wibaux, MT?
About 112 days between the median last spring frost and first fall frost.
What planting zone is Wibaux, MT?
Wibaux, MT is in USDA hardiness zone 4a.